Redundant solid state disk system via interconnect cards

ABSTRACT

A first interconnect card is configured, wherein a first controller is included in the first interconnect card. A second interconnect card coupled to the first interconnect card is configured, wherein a second controller is included in the second interconnect card. In response to a failure of the first controller included in the first interconnect card, the first interconnect card is controlled via the second controller included in the second interconnect card. In response to a failure of the second controller included in the second interconnect card, the second interconnect card is controlled via the first controller included in the first interconnect card.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 12/429,105filed on Apr. 23, 2009, which is incorporated herein by reference in itsentirety.

BACKGROUND

1. Field

The disclosure relates to a method, a system, and an article ofmanufacture for a redundant solid state disk system via interconnectcards.

2. Background

A solid state disk (SSD) may comprise a data storage device that usessolid state memory to store persistent digital data. Solid state disksmay include flash memory or memory of other types. Solid state disks maybe accessed much faster in comparison to electromechanically accesseddata storage devices, such as, hard disks.

Solid stated disks are available in a variety of form factors. Inaddition to solid state disks that fit into traditional hard disk formfactors, solid state disks may be incorporated into cards, such asPeripheral Component Interconnect Express (PCIE) cards or other types ofcards. For example, certain cards may package a certain amount of NANDflash devices along with a controller onto a PCIE form factor compliantcard. Although not a traditional disk format, such cards may be used toperform many of the functions performed by hard disks.

SUMMARY OF THE PREFERRED EMBODIMENTS

Provided are a method, a system, and an article of manufacture, in whicha first interconnect card is configured, wherein a first controller isincluded in the first interconnect card. A second interconnect cardcoupled to the first interconnect card is configured, wherein a secondcontroller is included in the second interconnect card. In response to afailure of the first controller included in the first interconnect card,the first interconnect card is controlled via the second controllerincluded in the second interconnect card. In response to a failure ofthe second controller included in the second interconnect card, thesecond interconnect card is controlled via the first controller includedin the first interconnect card.

In certain embodiments, the first interconnect card includes a firstplurality of solid state devices, wherein in response to determiningthat the first controller is operational the first plurality of solidstate devices are controlled by the first controller. The secondinterconnect card includes a second plurality of solid state devices,wherein in response to determining that the second controller isoperational the second plurality of solid state devices are controlledby the second controller.

In certain additional embodiments, data is mirrored from the firstplurality of solid state devices to the second plurality of solid statedevices. In response to a failure of the first controller included inthe first interconnect card, the first plurality of solid state devicesare controlled via the second controller included in the secondinterconnect card. In response to a failure of the second controllerincluded in the second interconnect card, the second plurality of solidstate devices are controlled via the first controller included in thefirst interconnect card.

In further embodiments, the first and second interconnect cards arePeripheral Component Interconnect Express (PCIE) cards. A firstconnector included in the first interconnect card is coupled to thefirst controller and a first plurality of expanders that are coupled tothe first plurality of solid state devices. A second connector includedin the second interconnect card is coupled to the second controller anda second plurality of expanders that are coupled to the second pluralityof solid state devices, wherein the first and the second connectors arecoupled. A physical replacement of the first controller is allowed inresponse to the failure of the first controller, wherein while the firstcontroller is being physically replaced the first plurality of solidstate devices remain operational and access is allowed to the firstplurality of solid state devices.

In additional embodiments, a third interconnect card is configured,wherein the first, second, and third interconnect cards communicate viaa fabric, wherein a third controller is included in the thirdinterconnect card, and wherein the first, second, and third interconnectcards remain operational in response to a failure of any one of thefirst, second, and third controllers.

In further embodiments, the first interconnect card includes a capacitorand a battery to provide power and maintain the first interconnect cardin an operational state, in response to a failure of external power tothe first interconnect card. The first interconnect card also comprisesa daughter card that includes the first controller, wherein the daughtercard is replaced to replace the first controller with a new controller,in response to the failure of the first controller, and wherein thefirst controller is operable as a Redundant Array of Independent Disk(RAID) controller. A plurality of replaceable solid state devices areincluded in the first interconnect card, wherein in response to afailure of a replaceable solid state device, the replaceable solid statedevice is replaced with a new solid state device while the firstinterconnect card is operational. Expanders are included in the firstinterconnect card to couple the first controller to the plurality ofsolid state devices. Furthermore, Serial Access Small Computer SystemInterface (SAS) connections are included in the first interconnect cardto communicate data to other devices and to components included in thefirst interconnect card.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings in which like reference numbers representcorresponding parts throughout:

FIG. 1 illustrates a block diagram of an exemplary interconnect card, inaccordance with certain embodiments;

FIG. 2 illustrates a block diagram that shows how a first interconnectcard is coupled to a second interconnect card in a computational device,in accordance with certain embodiments;

FIG. 3 illustrates a block diagram of a redundant system that includesat least a first interconnect card and a second interconnect card, inaccordance with certain embodiments;

FIG. 4 illustrates a flowchart that shows first operations implementedin the redundant system of FIG. 3, in accordance with certainembodiments;

FIG. 5 illustrates a flowchart that shows second operations implementedin the redundant system of FIG. 3, in accordance with certainembodiments;

FIG. 6 illustrates a block diagram of a redundant system that includesat least three interconnect cards that communicate via a fabric, inaccordance with certain embodiments;

FIG. 7 illustrates a block diagram of an exemplary augmentedinterconnect card, in accordance with certain embodiments;

FIG. 8 illustrates a flowchart that shows third operations implementedin the redundant system of FIG. 3, wherein the interconnect cards usedin the redundant system of FIG. 3 are the augmented exemplaryinterconnect cards shown in FIG. 7, in accordance with certainembodiments;

FIG. 9 illustrates a block diagram of a redundant system that usesSerial Attached Small Computer System Interface (SAS) connections, inaccordance with certain embodiments;

FIG. 10 illustrates a three dimensional diagram of an exemplaryinterconnect card, in accordance with certain embodiments; and

FIG. 11 illustrates a block diagram of a computational device that showscertain elements that may be included in the redundant system of FIG. 3,in accordance with certain embodiments.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanyingdrawings which form a part hereof and which illustrate severalembodiments. It is understood that other embodiments may be utilized andstructural and operational changes may be made.

Redundant Solid State Disk System

Critical data that should not be lost may be stored on a plurality ofsolid state disks. In order to provide redundancy, system software mayperform mirroring or configure a plurality of solid state disks into aRedundant Array or Independent Disks (RAID). Software RAID may not beadequate in terms of performance to exploit the fast performance ofsolid state disk drives. Certain embodiments not only achieve redundancyof data but also exploit the performance advantages of solid statedisks.

Certain embodiments provide a: PCIE form factor compliant card whichintegrates a RAID controller, Application Specific Integrated Circuit(ASIC), several NAND flash controllers and NAND flashes, and allowsinterconnection between a pair of cards for redundancy. If a solid statedevice card fails, there is enough spare capacity such that no cardneeds to be replaced until the second failure. Additionally, if the RAIDcontroller fails, in certain embodiments the RAID controller can bereplaced through a front bezel without affecting the NAND flashes. Incertain embodiments, the RAID controller may be a card that is pluggedinside the PCIE card. All solid state devices can be accessed via thesurviving RAID controller while the failing RAID controller is serviced.

In certain embodiments, each solid state device is packaged in some typeof DIMM form factor. In an exemplary embodiment, 6 SSD cards may befitted in a PCIE card. A Serial Attached Small Computer System Interface(SAS) fabric may be provided such that each RAID controller can secureaccess to each solid state disk. Even when the RAID controller is beingserviced, all solid state disks are accessible.

Exemplary Embodiments

FIG. 1 illustrates a block diagram of an exemplary interconnect card100, in accordance with certain embodiments. The interconnect card 100may comprise any hardware-implemented card or hardware-implementedadapter that may be coupled to a computational device, wherein thehardware-implemented card may include software or firmware forperforming various operations. The interconnect card 100 may residewithin a computational device or may be positioned such that theinterconnect card is removable from external slots present in thecomputational device. For example, in certain embodiments theinterconnect card 100 may be a PCIE card or a PCIE form factor complaintcard.

The interconnect card 100 includes at least a controller 102, aplurality of solid state devices 104 a . . . 104 n, a plurality ofexpanders 106 a . . . 106 m, and at least one connector 108.

The controller 102 controls the plurality of solid state devices 104 a .. . 104 n. The expanders 106 a . . . 106 m allow an expansion in thenumber of solid state devices 104 a . . . 104 n that may be controlledby the controller 102. For example, in certain embodiments two expandersmay allow the controller 102 to control sixteen solid state devices. Theconnector 108 may be used to connect to the controller 102 and also toconnect to the expanders 106 a . . . 106 m. For example, in FIG. 1,connecting element 110 provides a connection between the connector 108and the controller 102, connecting element 112 provides a connectionbetween the connector 108 and the expander 106 a, and connecting element114 provides a connection between the connector 108 and the expander 106m. Each of the connecting elements 110, 112, 114 may be implemented byone or more wires, via a bus, or via other mechanisms.

FIG. 2 illustrates a block diagram of a computational device 200 inwhich a first interconnect card 202 is coupled to a second interconnectcard 204 via an interconnecting element 206, in accordance with certainembodiments. In certain embodiments the interconnecting element 206 thatcouples the interconnect cards 202, 204 may be a SAS connection or someother type of connection. The interconnect cards 202, 204 may correspondto the interconnect card 100 that has been shown earlier in FIG. 1.

The interconnect card 202 includes a connector 208, a controller 210, aplurality of expanders 212 a . . . 212 p, and a plurality of solid statedevices 214 a . . . 214 q. The interconnect card 204 includes aconnector 216, a controller 218, a plurality of expanders 220 a . . .220 r, and a plurality of solid state devices 222 a . . . 222 t.

In certain embodiments, in response to a failure of the controller 210,the controller 218 may be used to control the solid state devices 214 a. . . 214 q via the connections 206, 224, 226, 228, 230, 232, 234, 236.The connections 206, 224, 226, 228. 230, 232, 234, 236 connect the solidstate devices 214 a . . . 214 q to the controller 218 via the connectors208, 216 and the expanders 212 a . . . 212 p. Similarly, in response toa failure of the controller 218, the controller 210 may be used tocontrol the solid state devices 222 a . . . 222 t. Therefore, thecomputational device 200 is a redundant system in which a failure of acontroller in any of the interconnect cards 202, 204 allows the solidstate devices 214 a . . . 214 q, 222 a . . . 222 t to remain operationaland be accessible.

FIG. 3 illustrates a block diagram of a redundant system 300corresponding to the computational device 200 of FIG. 2, wherein theredundant system 300 includes at least a first interconnect card 302 anda second interconnect card 304 that are coupled 306, in accordance withcertain embodiments.

The first interconnect card 302 includes a first controller 308 thatcontrols a first plurality of solid state devices 310 a . . . 310 j, andthe second interconnect card 304 includes a second controller 312 thatcontrols a second plurality of solid state devices 314 a . . . 314 k.

FIG. 4 illustrates a flowchart that shows first operations implementedin the redundant system 300 of FIG. 3, in accordance with certainembodiments. The operations illustrated in FIG. 4 may be implemented byone or more processors, application specific integrated circuits (ASIC),controllers, etc., that may be present in the redundant system 300.

Control starts at block 400, in which a first interconnect card 302 isconfigured, wherein a first controller 308 is included in the firstinterconnect card 302. A second interconnect card 304 coupled 306 to thefirst interconnect card 302 is configured (at block 402), wherein asecond controller 312 is included in the second interconnect card 304.

In response to a failure (reference numeral 404) of the first controller308 included in the first interconnect card 302, control proceeds toblock 406 in which the first interconnect card 302 is controlled via thesecond controller 312 included in the second interconnect card 304.

In response to a failure (reference numeral 408) of the secondcontroller 312 included in the second interconnect card 304, the secondinterconnect card 304 is controlled (at block 410) via the firstcontroller 308 included in the first interconnect card 302.

FIG. 5 illustrates a flowchart that shows second operations implementedin the redundant system 300 of FIG. 3, in accordance with certainembodiments. The operations illustrated in FIG. 5 may be implemented byone or more processors, application specific integrated circuits (ASIC),controllers, etc., that may be present in the redundant system 300.

Control starts at block 500, in which a first interconnect card 302 isconfigured, wherein a first controller 308 is included in the firstinterconnect card 302, and wherein the first interconnect card 302includes a first plurality of solid state devices 310 a . . . 310 j.Control proceeds to block 502 in which a second interconnect card 304coupled 306 to the first interconnect card 302 is configured, wherein asecond controller 312 is included in the second interconnect card 304,and wherein the second interconnect card 304 includes a second pluralityof solid state devices 314 a . . . 314 k. In certain embodiments, datais mirrored (at block 504) from the first plurality of solid statedevices 310 a . . . 3.10 j to the second plurality of solid statedevices 314 a . . . 314 k. In certain alternative embodiments mirroringof data is not performed, but the solid state devices 310 a . . . 310 j,314 a . . . 314 k are collectively used for storing critical data,wherein critical data is data whose loss cannot be tolerated.

In response to a failure (reference numeral 506) of the first controller308, control proceeds to block 508 in which the first plurality of solidstate devices 310 a . . . 310 j are controlled via the second controller312 included in the second interconnect card 304, and the secondplurality of solid state devices 314 a . . . 314 k continue to remaincontrolled via the second controller 312.

In response to a failure (reference numeral 510) of the secondcontroller 312, control proceeds to block 512 in which the secondplurality of solid state devices 314 a . . . 314 k are controlled viathe first controller 308 included in the first interconnect card 302,and the first plurality of solid state devices 310 a . . . 310 jcontinue to remain controlled via the first controller 308.

In certain embodiments, the first and second interconnect cards 302, 304of the redundant system 300 in which the operations shown in FIGS. 4 and5 are performed are Peripheral Component Interconnect Express (PCIE)cards. A physical replacement of the first controller 308 is allowed inresponse to the failure of the first controller 308, wherein while thefirst controller 308 is being physically replaced the first plurality ofsolid state devices 310 a . . . 310 j remain operational and access isallowed to the first plurality of solid state devices 310 a . . . 310 j.The first controller 308 may be implemented in the form of a removablecard within the first interconnect card 302. Similarly, the secondcontroller 312 may also be physically replaced.

FIG. 6 illustrates a block diagram of a redundant system 600 thatincludes at least three interconnect cards 602, 604, 606 thatcommunicate via a fabric 610, in accordance with certain embodiments.The first, second, and third interconnect cards 602, 604, 606 includefirst, second, and third controllers 612, 614, 616 respectively. Incertain embodiments, the first, second, and third interconnect cards602, 604, 606 remain operational in response to a failure of any one ofthe first, second, and third controllers 612, 614, 616. The solid statedevices that may be present in the interconnect cards 602, 604, 606 alsostay operational.

FIG. 7 illustrates a block diagram of an exemplary augmentedinterconnect card 700, in accordance with certain embodiments. Theaugmented interconnect card 700 includes certain enhancements includedin the interconnect card 100 shown in FIG. 1.

The augmented interconnect card 700 is a PCIE card in which thecontroller 102 is included in a replaceable daughter card 702 and thesolid state devices 104 a . . . 104 n are replaceable devices. Theaugmented interconnect card 700 may also include a capacitor 706 and abattery 708. In certain embodiments, the capacitor 706 may comprise asupercapacitor that stores charge that is adequate to keep the augmentedinterconnect card operational for a certain period of time even whenexternal power supply to the augmented interconnect card has failed.

FIG. 8 illustrates a flowchart that shows third operations implementedin the redundant system 300 of FIG. 3, wherein each of the interconnectcards 302, 304 used in the redundant system of FIG. 3 is comprised ofthe augmented exemplary interconnect card 700 (shown in FIG. 7), inaccordance with certain embodiments.

Control starts at block 800 in which an interconnect card 700 isoperational. From block 800, control may proceed in parallel to blocks802, 804, 806.

At block 802 a determination is made as to whether a failure of externalpower to the augmented interconnect card 700 has occurred. If so, thecapacitor 706 and/or the battery 708 provides (at block 808) power tothe augmented interconnect card 700 and maintains the augmentedinterconnect card 700 in an operational state. If not, a determinationis made once again as to whether to whether a failure of external powerto the augmented interconnect card 700 has occurred.

At block 804 a determination is made as to whether the controller 102included in the daughter card 702 has failed. If so, then the existingdaughter card 702 is replaced (at block 810) with a new daughter cardthat includes a new controller while the interconnect card 700 isoperational. If not, a determination is made once again as to whetherthe controller 102 included in the daughter card 702 has failed

At block 806, a determination is made as to whether a failure of areplaceable solid state device has occurred. If so, the failedreplaceable solid state device is replaced (at block 812) with a newsolid state device while the interconnect card 700 is operational.

Therefore, FIGS. 7-8 illustrate certain embodiments in which acontroller may be replaced by replacing the daughter card that includesthe controller. Furthermore, a solid state device may be replaced whilean interconnect card is operational. Additionally, in the event of afailure of external power to an interconnect card, capacitors and/orbatteries included in the interconnect card may maintain theinterconnect card in an operational state.

FIG. 9 illustrates a block diagram of an exemplary redundant system 900that uses SAS connections, in accordance with certain embodiments. SAS,i.e., serial attached SCSI connections 902 may be used for high speeddata transfer between two interconnect cards 904, 906. The SASconnections 902 show four exemplary lines each carrying 3 Gbytes ofdata. The interconnections among components of the interconnect cardsmay also comprise SAS connections (e.g., SAS connection 903).

The controller of each of the interconnect cards 904, 906 may bereferred to as Redundant Array of Independent Disks (RAID) controllers908, 910, wherein the RAID controllers 908, 910 may in certainembodiments implement a RAID system with the solid state devices (SSD)shown in FIG. 9.

FIG. 10 illustrates a three dimensional diagram of an exemplaryinterconnect card 1000, in accordance with certain embodiments. Theinterconnect card 1000 is a PCIE card 1002 that includes the controllerin a daughter card (shown via reference numeral 1002), solid statedevices 1006, batteries and/or supercapacitors 1008, and one or moreports 1010 for connections to other cards or devices.

Therefore, FIGS. 1-10 illustrate certain embodiments in which aredundant system is created by coupling a plurality of interconnectcards that include solid state devices. In response to a failure of acontroller within a first interconnect card, an operational controllerwithin a second interconnect card starts controlling the solid statedevices present in the first interconnect card.

Additional Embodiment Details

The described techniques may be implemented as a method, apparatus orarticle of manufacture involving software, firmware, micro-code,hardware and/or any combination thereof. The term “article ofmanufacture” as used herein refers to code or logic implemented in amedium, where such medium may comprise hardware logic [e.g., anintegrated circuit chip, Programmable Gate Array (PGA), ApplicationSpecific Integrated Circuit (ASIC), etc.] or a computer readable storagemedium, such as magnetic storage medium (e.g., hard disk drives, floppydisks, tape, etc.), optical storage (CD-ROMs, optical disks, etc.),volatile and non-volatile memory devices [e.g., Electrically ErasableProgrammable Read Only Memory (EEPROM), Read Only Memory (ROM),Programmable Read Only Memory (PROM), Random Access Memory (RAM),Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM),flash, firmware, programmable logic, etc.]. Code in the computerreadable storage medium is accessed and executed by a processor. Themedium in which the code or logic is encoded may also comprisetransmission signals propagating through space or a transmission media,such as an optical fiber, copper wire, etc. The transmission signal inwhich the code or logic is encoded may further comprise a wirelesssignal, satellite transmission, radio waves, infrared signals,Bluetooth, etc. The transmission signal in which the code or logic isencoded is capable of being transmitted by a transmitting station andreceived by a receiving station, where the code or logic encoded in thetransmission signal may be decoded and stored in hardware or a computerreadable medium at the receiving and transmitting stations or devices.Additionally, the “article of manufacture” may comprise a combination ofhardware and software components in which the code is embodied,processed, and executed. Of course, those skilled in the art willrecognize that many modifications may be made without departing from thescope of embodiments, and that the article of manufacture may compriseany information bearing medium. For example, the article of manufacturecomprises a storage medium having stored therein instructions that whenexecuted by a machine results in operations being performed.

Certain embodiments can take the form of an entirely hardware embodimentor an embodiment comprising hardware processing software elements Incertain embodiments, selected operations may be implemented in microcodethat is present in one or more computational devices.

Furthermore, certain embodiments can take the form of a computer programproduct accessible from a computer usable or computer readable mediumproviding program code for use by or in connection with a computer orany instruction execution system. For the purposes of this description,a computer usable or computer readable medium can be any apparatus thatcan contain, store, communicate, propagate, or transport the program foruse by or in connection with the instruction execution system,apparatus, or device.

The medium can be an electronic, magnetic, optical, electromagnetic,infrared, or semiconductor system (or apparatus or device) or apropagation medium. Examples of a computer-readable medium include asemiconductor or solid state memory, magnetic tape, a removable computerdiskette, a random access memory (RAM), a read-only memory (ROM), arigid magnetic disk and an optical disk. Current examples of opticaldisks include compact disk—read only memory (CD-ROM), compactdisk—read/write (CD-R/W) and DVD.

The terms “certain embodiments”, “an embodiment”, “embodiment”,“embodiments”, “the embodiment”, “the embodiments”, “one or moreembodiments”, “some embodiments”, and “one embodiment” mean one or more(but not all) embodiments unless expressly specified otherwise. Theterms “including”, “comprising”, “having” and variations thereof mean“including but not limited to”, unless expressly specified otherwise.The enumerated listing of items does not imply that any or all of theitems are mutually exclusive, unless expressly specified otherwise. Theterms “a”, “an” and “the” mean “one or more”, unless expressly specifiedotherwise.

Devices that are in communication with each other need not be incontinuous communication with each other, unless expressly specifiedotherwise. In addition, devices that are in communication with eachother may communicate directly or indirectly through one or moreintermediaries. Additionally, a description of an embodiment withseveral components in communication with each other does not imply thatall such components are required. On the contrary a variety of optionalcomponents are described to illustrate the wide variety of possibleembodiments.

Further, although process steps, method steps, algorithms or the likemay be described in a sequential order, such processes, methods andalgorithms may be configured to work in alternate orders. In otherwords, any sequence or order of steps that may be described does notnecessarily indicate a requirement that the steps be performed in thatorder. The steps of processes described herein may be performed in anyorder practical. Further, some steps may be performed simultaneously, inparallel, or concurrently.

When a single device or article is described herein, it will be apparentthat more than one device/article (whether or not they cooperate) may beused in place of a single device/article. Similarly, where more than onedevice or article is described herein (whether or not they cooperate),it will be apparent that a single device/article may be used in place ofthe more than one device or article. The functionality and/or thefeatures of a device may be alternatively embodied by one or more otherdevices which are not explicitly described as having suchfunctionality/features. Thus, other embodiments need not include thedevice itself.

FIG. 11 illustrates a block diagram that shows certain elements that maybe included in the redundant system 300, 900 in accordance with certainembodiments. The redundant system 300, 900 may also be referred to as asystem 1100, and may include a circuitry 1102 that may in certainembodiments include at least a processor 1104. In addition to theinterconnect cards shown earlier, the system 1100 may also include amemory 1106 (e.g., a volatile memory device), and storage 1108. Thestorage 1108 may include a non-volatile memory device (e.g., EEPROM,ROM, PROM, RAM, DRAM, SRAM, flash, firmware, programmable logic, etc.),magnetic disk drive, optical disk drive, tape drive, etc. The storage1108 may comprise an internal storage device, an attached storage deviceand/or a network accessible storage device. The system 1100 may includea program logic 1110 including code 1112 that may be loaded into thememory 1106 and executed by the processor 1104 or circuitry 1102. Incertain embodiments, the program logic 1110 including code 1112 may bestored in the storage 1108. In certain other embodiments, the programlogic 1110 may be implemented in the circuitry 1102. Therefore, whileFIG. 11 shows the program logic 1110 separately from the other elements,the program logic 1110 may be implemented in the memory 1106 and/or thecircuitry 1102.

Certain embodiments may be directed to a method for deploying computinginstruction by a person or automated processing integratingcomputer-readable code into a computing system, wherein the code incombination with the computing system is enabled to perform theoperations of the described embodiments.

At least certain of the operations illustrated in FIGS. 1-11 may beperformed in parallel as well as sequentially. In alternativeembodiments, certain of the operations may be performed in a differentorder, modified or removed.

Furthermore, many of the software and hardware components have beendescribed in separate modules for purposes of illustration. Suchcomponents may be integrated into a fewer number of components ordivided into a larger number of components. Additionally, certainoperations described as performed by a specific component may beperformed by other components.

The data structures and components shown or referred to in FIGS. 1-11are described as having specific types of information. In alternativeembodiments, the data structures and components may be structureddifferently and have fewer, more or different fields or differentfunctions than those shown or referred to in the figures. Therefore, theforegoing description of the embodiments has been presented for thepurposes of illustration and description. It is not intended to beexhaustive or to limit the embodiments to the precise form disclosed.Many modifications and variations are possible in light of the aboveteaching.

1. A method, comprising: configuring, by a processor, a firstinterconnect card, wherein a first controller is included in the firstinterconnect card, wherein the first interconnect card includes acapacitor to provide power and to maintain the first interconnect cardin an operational state, in response to a failure of external power tothe first interconnect card; configuring a second interconnect cardcoupled to the first interconnect card, wherein a second controller isincluded in the second interconnect card; in response to a failure ofthe first controller included in the first interconnect card,controlling the first interconnect card via the second controllerincluded in the second interconnect card; and in response to a failureof the second controller included in the second interconnect card,controlling the second interconnect card via the first controllerincluded in the first interconnect card.
 2. The method of claim 1,wherein the first interconnect card also includes a battery in additionto the capacitor to provide power and to maintain the first interconnectcard in an operational state, in response to a failure of external powerto the first interconnect card.
 3. The method of claim 1, wherein thefirst controller is included in a daughter card, the method furthercomprising: replacing the daughter card, to replace the first controllerwith a new controller, in response to the failure of the firstcontroller.
 4. The method of claim 1, wherein the first controller isoperable as a Redundant Array of Independent Disk (RAID) controller. 5.The method of claim 1, wherein the first controller comprises aplurality of replaceable solid state devices, wherein in response to afailure of a replaceable solid state device, the replaceable solid statedevice is replaced with a new solid state device while the firstinterconnect card is operational.
 6. A computer readable storage medium,wherein code stored in the computer readable storage medium in responseto being executed by a processor performs operations, the operationscomprising: configuring a first interconnect card, wherein a firstcontroller is included in the first interconnect card, wherein the firstinterconnect card includes a capacitor to provide power and to maintainthe first interconnect card in an operational state, in response to afailure of external power to the first interconnect card; configuring asecond interconnect card coupled to the first interconnect card, whereina second controller is included in the second interconnect card; inresponse to a failure of the first controller included in the firstinterconnect card, controlling the first interconnect card via thesecond controller included in the second interconnect card; and inresponse to a failure of the second controller included in the secondinterconnect card, controlling the second interconnect card via thefirst controller included in the first interconnect card.
 7. Thecomputer readable storage medium of claim 6, wherein the firstinterconnect card also includes a battery in addition to the capacitorto provide power and to maintain the first interconnect card in anoperational state, in response to a failure of external power to thefirst interconnect card.
 8. The computer readable storage medium ofclaim 6, wherein the first controller is included in a daughter card,the operations further comprising: replacing the daughter card, toreplace the first controller with a new controller, in response to thefailure of the first controller.
 9. The computer readable storage mediumof claim 6, wherein the first controller is operable as a RedundantArray of Independent Disk (RAID) controller.
 10. The computer readablestorage medium of claim 6, wherein the first controller comprises aplurality of replaceable solid state devices, wherein in response to afailure of a replaceable solid state device, the replaceable solid statedevice is replaced with a new solid state device while the firstinterconnect card is operational.
 11. A system, comprising: a firstinterconnect card; a second interconnect card coupled to the firstinterconnect card; a first controller included in the first interconnectcard; and a second controller included in the second interconnect card,and wherein the system performs operations, the operations comprising:configuring the first interconnect card, wherein the first interconnectcard includes a capacitor to provide power and to maintain the firstinterconnect card in an operational state, in response to a failure ofexternal power to the first interconnect card; configuring the secondinterconnect card; in response to a failure of the first controllerincluded in the first interconnect card, controlling the firstinterconnect card via the second controller included in the secondinterconnect card; and in response to a failure of the second controllerincluded in the second interconnect card, controlling the secondinterconnect card via the first controller included in the firstinterconnect card.
 12. The system of claim 11, wherein the firstinterconnect card also includes a battery in addition to the capacitorto provide power and to maintain the first interconnect card in anoperational state, in response to a failure of external power to thefirst interconnect card.
 13. The system of claim 11, wherein the firstcontroller is included in a daughter card, the operations furthercomprising: replacing the daughter card, to replace the first controllerwith a new controller, in response to the failure of the firstcontroller.
 14. The system of claim 11, wherein the first controller isoperable as a Redundant Array of Independent Disk (RAID) controller. 15.The system of claim 11, wherein the first controller comprises aplurality of replaceable solid state devices, wherein in response to afailure of a replaceable solid state device, the replaceable solid statedevice is replaced with a new solid state device while the firstinterconnect card is operational.